An integrated coal gasification combined cycle facility is a power generation facility configured to gasify coal and use the coal gasification and combined cycle power generation in combination, and thereby intended for power generation that is more efficient and more environmentally friendly than conventional coal fired power generation. One major advantage of such an integrated coal gasification combined cycle facility is that coal, which is an abundantly available resource, is usable therefor. It is known that this advantage becomes even greater when coal used therefor is diversified in kind.
A conventional integrated coal gasification combined cycle facility typically includes a coal feed unit, a coal gasifier, a char recovery unit, a gas purification facility, a gas turbine facility, a steam turbine facility, and an exhausted heat recovery steam generator. Accordingly, product gas (combustible gas) is produced by supplying coal (powdered coal) to the coal gasifier by the coal feed unit, introducing a gasifying agent (such as air, oxygen-enriched air, oxygen, or steam) to the coal gasifier, and converting the coal into combustion gas in this coal gasifier. Thereafter, an unreacted portion (char) of the coal is removed from the product gas in the char recovery unit, and then, the product gas undergoes gas purification. Then, the product gas is fed into the gas turbine facility, and is combusted to generate high-temperature and high-pressure combustion gas, which drives a turbine. Thermal energy from flue gas that results from driving of the turbine is recovered by the exhausted heat recovery steam generator, so that steam is generated and fed into the steam turbine facility to drive a turbine. As a result, power is generated. On the other hand, the flue gas from which thermal energy has been recovered is emitted into the atmosphere through a stack.
The char recovery unit in the above described integrated coal gasification combined cycle facility uses separation devices at multiple stages to remove contained char from product gas produced in the coal gasifier. In addition, the char thus recovered is returned to the coal gasifier in the predetermined amount by a char feed device. That is, a bin system is applied to this process. A typical bin system includes: one bin (or more than one bin); a plurality of char discharge lines that discharges, into this bin, the char recovered from the respective separation devices; and a plurality of char feed lines that feeds, into a plurality of hoppers (or one hopper), the char recovered and held in the bin.
Note that examples of conventional char recovery unit include those described in Patent Literatures 1 to 3 listed below.